Method for inter-scene transitions

ABSTRACT

A method and system for creating a transition between a first scene and a second scene on a computer system display, simulating motion. The method includes determining a transformation that maps the first scene into the second scene. Motion between the scenes is simulated by displaying transitional images that include a transitional scene based on a transitional object in the first scene and in the second scene. The rendering of the transitional object evolves according to specified transitional parameters as the transitional images are displayed. A viewer receives a sense of the connectedness of the scenes from the transitional images. Virtual tours of broad areas, such as cityscapes, can be created using inter-scene transitions among a complex network of pairs of scenes.

This application is a continuation of, and therefore claims priority to,U.S. patent application Ser. No. 16/042,309 (the '309 application—U.S.Pat. No. 10,304,233), filed Jul. 23, 2018, entitled “Method forInter-Scene Transitions,” the disclosure of which is incorporated hereinby reference. The '309 application is a continuation of, and thereforeclaims priority to, U.S. patent application Ser. No. 14/969,669 (the'669 application—U.S. Pat. No. 10,032,306), filed Dec. 15, 2015,entitled “Method for Inter-Scene Transitions”, the disclosure of whichis incorporated herein by reference. The '669 application is acontinuation of, and therefore claims priority from, U.S. patentapplication Ser. No. 14/090,654 (the '654 application—Abandoned), filedNov. 26, 2013, entitled “Method for Inter-Scene Transitions”, thedisclosure of which is incorporated herein by reference. The '654application is a continuation of, and therefore claims priority from,U.S. patent application Ser. No. 11/271,159 (the '159application—Abandoned), filed Nov. 11, 2005, entitled “Method forInter-Scene Transitions”, the disclosure of which is incorporated hereinby reference. The '159 application claims priority from U.S. provisionalpatent application Ser. No. 60/712,356 (the '356 application), filedAug. 30, 2005, entitled “Method for Inter-Scene Transitions”, thedisclosure of which is incorporated herein by reference. The '159application also claims priority from U.S. provisional patentapplication Ser. No. 60/627,335, filed Nov. 12, 2004, entitled “Methodfor Inter-Scene Transitions,” which is incorporated herein by reference.

TECHNICAL FIELD

The invention relates to computer graphics methods and systems and, inparticular, to methods and systems for creating smooth transitionsbetween two or more related images or panoramas on a computer display.

BACKGROUND

Virtual tours have become a frequently used technique for providingviewers with information about scenes of interest. Such tours canprovide a photorealistic, interactive and immersive experience of ascene or collection of scenes. These tours can incorporate one or moreof a wide variety of graphic display techniques in representing thescenes.

One effective technique for presenting information as part of thesetours is display of a panorama or panoramic image. Panoramic viewers candisplay images with wide fields of view, while maintaining detail acrossthe entire picture. Several steps are required for creation and displayof these panoramas: image capture, image “stitching”, and panoramadisplay (or viewing). The first step is capturing an image of the scene100, which is also known as the acquisition step. Multiple photographsare typically taken from various angles from a single position 110 inspace, as shown in FIG. 1. Regular cameras and equipment may be used andspecialized hardware is not usually required. The photographic imagestaken are then “stitched” together using stitching techniques, as areknown in the art, to provide a substantially seamless view of a scenefrom a given position. FIG. 2 shows an example of a scene in twopanoramic formats: a sphere map 200, 220 and a cube map 210, 230. Theunwrapped stitched image 200 maps onto a spherical geometry 220, and thepanorama virtually replicates the photography acquisition position whenviewed from the center of the sphere. The process works similarly withcube map panoramas. Other types of panoramic projections may beemployed, but the process is similar. Note that images may be thought ofas partial panoramas. The final step is display of or viewing thepanorama, as illustrated in FIG. 3. The stitched together images areviewed interactively using panorama-viewing techniques, as are known inthe art. In FIG. 3, the acquisition position 310 in virtual space in thecenter of the sphere is shown for a spherical panorama 300. Also shownis the pin-hole camera projection frustum 320 that represents oneportion of the panoramic image that may be viewed on the display.

Current panoramic virtual tours have significant limitations. Theinherent nature of panoramas (including regular photographs and images),is that panoramas are taken from a single acquisition position, and,thus, the images are static. To describe a broader area, i.e., beyond aview from a point in space, panoramic virtual tours typically employ a“periscope view”—the end user “pops” into a point in space, looksaround, and then instantaneously “pops” into another position in spaceto navigate through a wider area. Assuming a simple case of twopanoramic scenes, even when the acquisition positions are very close, itis often difficult for the viewer to mentally connect the two scenes.The two panoramas are not inherently capable of describing how thepanoramas are connected and oriented with respect to each other. Withthese limitations, it is difficult for the viewer to understand thespace, sense of orientation, and scale of a wider area with currentvirtual tours.

SUMMARY OF THE INVENTION

In a first embodiment of the invention, there is provided a method forcreating a transition between a first scene and a second scenesimulating motion in a computer system having a display. The first sceneis observed from a first viewpoint and includes a feature. The secondscene is observed from a second viewpoint and includes a second feature.The method includes first graphically identifying on the display thefeature in the first scene and the feature in the second scene anddetermining a transformation mapping the first scene into the secondscene using the two features. Then, one or more transitional images arecreated that include at least one transitional scene based on thefeature in the first scene and on the feature in the second scene, suchthat there is simulated motion from the first scene to the second scene.

In another embodiment of the invention, a method is provided fordisplaying a transition between a first scene and a second scenesimulating motion on a computer system display. The first scene isobserved from a first viewpoint and includes a first feature, and thesecond scene is observed from a second viewpoint and includes a secondfeature. The method includes displaying a navigational icon embedded inthe first scene. When the navigational icon is activated, at least onetransitional image is displayed that includes at least one transitionalscene based on the first feature and on the second feature, such thatthere is simulated motion from the first scene to the second scene.

In a further embodiment of the invention, a method is provided fordisplaying a transition between a first scene and a selected scenesimulating motion on a computer system display. The first scene isobserved from a first viewpoint and includes a first feature, and theselected scene is observed from a second viewpoint and includes a secondfeature. The method includes displaying the first scene; receiving anindication of the location of the selected scene. When the location ofthe selected location is received, at least one transitional image isdisplayed that includes at least one transitional scene based on thefirst feature and on the second feature, such that there is simulatedmotion from the first scene to the selected scene. In specificembodiment of the invention, the indication may be received from searchengine output, or a user selection from a list or activation of an iconanywhere on a display, etc.

In a further embodiment of the invention, a method is provided fordisplaying a transition between a first scene and a second scene andbetween the second scene and a third scene simulating motion on acomputer system display. The first scene is observed from a firstviewpoint and includes a first feature; the second scene is observedfrom a second viewpoint and includes a second feature; and the thirdscene is observed from a third viewpoint and includes a third feature.The method includes:

providing a first transitional image that includes at least onetransitional scene based on the first feature and on the second feature,such that there is simulated motion from the first scene to the secondscene; and providing a second transitional image that includes at leastone transitional scene based on the second feature and on the thirdfeature, such that there is simulated motion from the second viewpointto the third viewpoint. The first transitional image and the secondtransitional image are formed without determining the absolute positionsand orientations in a frame of reference of each of the first, secondand third scenes.

In another embodiment of the invention, a method is provided fordisplaying a transition between a first scene and a selected scenesimulating motion on a computer system display. The first scene isobserved from a first viewpoint and includes a first feature; a secondscene is observed from a second viewpoint and includes a second feature;and the selected scene is observed from a selected scene viewpoint. Themethod includes: displaying the first scene; receiving an indication ofthe location of the selected scene viewpoint; and determining a routefrom the first viewpoint to the selected scene viewpoint, where theroute includes the second viewpoint. When the indication of the locationof the selected scene viewpoint is received, a transitional image isdisplayed that includes at least one transitional scene based on thefirst feature and on the second feature, such that there is simulatedmotion from the first scene to the second scene.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing features of the invention will be more readily understoodby reference to the following detailed description, taken with referenceto the accompanying drawings in which:

FIG. 1 illustrates capturing images to form a panorama;

FIG. 2 shows an example of a scene in two panoramic formats—a sphere mappanorama and a cube map panorama;

FIG. 3 illustrates viewing a spherical panorama;

FIG. 4 shows an overview flow diagram for a method of creating asupertour, according to an embodiment of the invention;

FIG. 5 shows an overview flow diagram for a method of creatinginter-scene motion, according to an embodiment of the invention;

FIG. 6 illustrates the relationship between an image plane and itscorresponding world plane, in an embodiment of the invention;

FIG. 7 illustrates the relationship between a feature in the image planeand its corresponding world plane image, in the illustration of FIG. 6;

FIG. 8 illustrates selection of points of a perspective rectangle in theimage plane according to an embodiment of the invention;

FIG. 9 illustrates interactive edge selection and movement according toan embodiment of the invention;

FIG. 10 is a flow diagram for the definition of a perspective rectangleaccording to an embodiment of the invention;

FIG. 11 illustrates generation of a normal vector to a perspectiverectangle according to an embodiment of the invention;

FIG. 12 illustrates computing a vanishing vector, according to anembodiment of the invention;

FIG. 13 shows two input source image spherical panoramas to illustratethe process for a perspective rectangle tool, according to an embodimentof the invention;

FIG. 14 illustrates corresponding features from the panoramas of FIG. 13in image and in world space;

FIG. 15 illustrates computing the normal vector to a rectangle in worldspace prior to rotating one image to align the image to the direction ofanother image, for the embodiment of the invention of FIG. 13;

FIG. 16 shows translation of one image to complete the alignment of oneimage to another image in world space for the embodiment of theinvention of FIG. 13;

FIG. 17 illustrates the geometrical construct that determines thesolution point for the translation of FIG. 16;

FIG. 18 shows three representations of an interior to illustratecreation of transitional objects using 3D geometry and texture mapping,according to an embodiment of the invention;

FIG. 19 illustrates the process of identifying a footprint for theprocess of FIG. 18;

FIG. 20 shows the completed footprint started in FIG. 19;

FIG. 21 illustrates extruding the footprint of FIGS. 19-20;

FIG. 22 shows completion of the extrusion process of FIG. 21;

FIGS. 23-25 illustrate the process for a transitional object creationtool, according to an embodiment of the invention;

FIG. 26 is a third person's view of the output of the transitionalobject creation process of FIGS. 23-25;

FIG. 27 illustrates modeling a transition from a first scene to a secondscene using a virtual camera, according to an embodiment of theinvention;

FIG. 28 shows point along the camera path, for the embodiment of FIG.27;

FIG. 29 shows the view at point along the path of FIG. 28;

FIG. 30 shows a different transition sequence with differenttransitional objects for the room shown in FIGS. 27-29, according to anembodiment of the invention;

FIG. 31 shows an exemplary user interface for a transitional parametereditor according to an embodiment of the invention;

FIG. 32 shows a close-up view the transitional parameter editor of FIG.31;

FIG. 33 illustrates moving the time point in the timeline for thetransitional parameter editor of FIG. 31;

FIG. 34 shows the effects of motion blurring and saturation adjustmenttransitional parameters on a scene view, according to an embodiment ofthe invention;

FIGS. 35-37 illustrate the morphing transitional parameter according toan embodiment of the invention;

FIGS. 38-39 provide an example of an inter-scene transition usingmorphing according to an embodiment of the invention;

FIGS. 40-42 provide an example of an inter-scene transition for twoscenes where exact features do not correspond, according to anembodiment of the invention;

FIGS. 43-44 provide an example of an inter-scene transition for twoscenes without rectangular features to correspond, according to anembodiment of the invention

FIG. 45 shows an overview flow diagram for a method of creating activeelements, according to an embodiment of the invention;

FIG. 46 shows a navigational icon active element, according to anembodiment of the invention;

FIG. 47 shows an example of active elements embedded into scenes,according to an embodiment of the invention;

FIGS. 48-52 illustrate a process for creating active elements using anactive element creator embodiment of the invention;

FIG. 53 shows a hotel banner active element, according to an embodimentof the invention;

FIG. 54 shows a virtual kiosk active element, according to an embodimentof the invention;

FIG. 55 is a flow diagram of a method for creating a supertour accordingto an embodiment of the invention;

FIG. 56 shows a display combining an overview map with perspective viewof corresponding locations in the supertour, according to an embodimentof the invention;

FIGS. 57-58 show scripting and orientation matching in a supertour,according to an embodiment of the invention;

FIG. 59 is a flow diagram of a method for publishing a supertouraccording to an embodiment of the invention;

FIG. 60 shows publication of an exemplary supertour, according to anembodiment of the invention;

FIGS. 61-70 show displayed views from an exemplary supertour of MiamiBeach, Fla. created according to an embodiment of the invention; and

FIG. 71 shows an example of a list where selection of an item causesmotion to a scene, according to an embodiment of the invention.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

Note that as used in this description and the accompanying claims, thefollowing terms shall have the meanings indicated, unless the contextotherwise requires: The term “perspective view” shall mean a 2D view ofan image in a world plane projected on an image plane. The image planewill frequently be a display surface, but in general, may be any plane.A “perspective rectangle” shall mean a 2D polygon in a perspective viewwhich is a projection of a rectangle in world space onto the imageplane. A “transitional parameter” shall mean a measure of thecontribution of a first image versus a second image to a transitionalobject formed from a combination of the first image and the secondimage. For example, if the transitional object is derived from alphablending the first image and the second image, the transitionalparameter measures the degree of transparency and opacity of thecontribution of each image to the transitional object. An “activeelement” shall mean an icon displayed in an image such that selection ofthe icon by an input device initiates an action. A “navigational icon”shall mean an active element icon displayed in an image such thatselection of the icon by an input device causes a displayed image of ascene to update.

In broad overview, embodiments of the invention provide a system and amethod that simulate smooth motion between images of two or moreconnected locations or scenes. Simulated motion provides a sense oforientation and an understanding of the space to users navigatingthrough a series of images of locations. To navigate from one image toanother, a user may select a portion of a first scene that connects to asecond scene. The view is then transitioned to the second scene. Thistype of navigation may be disorienting if the second scene simplyreplaces the first scene—there is no sense of motion between the scenesto emphasize the geographic connection between them. Instead, motionbetween the two scenes may be simulated to provide the viewer a bettersense of the relationships between the two scenes, including a sense ofspace and orientation.

In further embodiments of the invention, this concept of simulatingmotion between images can be extended to create a connected network ofmultiple image pairs forming a tour of a space, such as a neighborhood,a boulevard, or even a town or city. Such a network of scenes will becalled below a “supertour.” The term “supertour” is used for conveniencein description and not by way of limitation: the network of images mayextend from two images to an arbitrarily large number of images. Anoverview flow diagram for a method of creating a supertour is shown inFIG. 4. Once input photographs and panoramas, also known as “sourceimages,” of a desired supertour location have been acquired 400, thesupertour may be created a pair of source images at a time throughinter-scene motion creation 410. Once transitions between scenes havebeen created, active elements may be added to the scenes to provideenhanced user interactivity 420, e.g., a navigational icon may beincluded to activate a transition to the next space, or a virtualinformational kiosk may provide amplifying information about a locationupon activation. Next, scene viewers, inter-scene motion generators andactive elements may be coupled 430 together with maps, etc, to create aconnected and complex virtual experience of a captured space. Thesupertour content may then be published 440 for viewing by an end user.Illustrative embodiments of these steps are provided below.

One method of providing a sense of connection between scenes usestechniques known as zooming and fading. From an initial panorama orimage, the viewer orients towards the second scene (panorama or image),zooms in by varying the field-of-view (“FOV”) of a virtual camera, thenfades out of the first panorama, then fades into the second panorama.This technique, may provide some sense of orientation, but is verydependent on the scene—how closely the panoramic images have beenacquired, whether the scenes contain substantial amounts of commonvisual features, and the complexity of visibility and occlusions amongthe objects within the scene. Otherwise, zooming and fading works nobetter than “popping” into the destination panorama without thezoom-fade effects. Furthermore, zooming into an image cannot properlysimulate moving in three-dimensional space. Note that zooming into aflat image is the same as “having a closer look” at an image, and doesnot simulate motion in 3D space. Realistic motion heavily depends on theparallax effect as relative positions between objects and camerachanges.

Another method of providing a simulation of motion between two images isto create a physical movie of the motion between images, which is playedwhen a user chooses to move between two scenes. Capturing an actualmovie between positions in physical space could be done using a videocamera, and other camera positioning equipment. This approach of usingmovies is particularly useful for transitioning between images on Webpages. Because most Web browsers include software that is capable ofplaying streaming video or other digital movie or video formats, noadditional software is needed to display such movies. Creating actualphysical movies for transitions between scenes can be time consuming andexpensive to acquire, especially for large environments, e.g.cityscapes. The movies also require significant data and postprocessing. Because of differences in points-of-view, it is typicallynecessary to create separate movies for each direction in which motionbetween images or panoramas is desired. Thus, for movement between twoimages, two movies are needed—one movie for movement from the firstimage to the second, and a different movie for movement from the secondimage to the first. This further complicates the acquisition process,since accurate connections of the bidirectional movies are important increating seamless movies and images/panoramas. Specialized equipment aswell as a crew of people are necessary for such endeavors.

Another method of simulating motion between two images involves creatinga three-dimensional model that represents the path between two images.Once such a three-dimensional model exists, motion between the imagescan be simulated by moving the position of a virtual camera in thethree-dimensional model. This approach provides a high degree offlexibility, permitting a user to view the area represented by the modelfrom any vantage point. Techniques such as those illustrated in U.S.patent application Ser. No. 10/780,500, entitled “Modeling and EditingImage Panoramas,” which is incorporated herein by reference, may be usedto create three dimensional models from panoramic images. However, thesetechniques create visual artifacts and seams, since photo-texturedmodels have static texture maps.

In various embodiments of the present invention, a method and a systemare provided for generating a substantially seamless transition betweentwo scenes—a “first scene” and a “second scene”—simulating motion on acomputer display screen. The first scene is observed from a firstviewpoint and the second scene is observed from a second viewpoint.These scenes may be a single source image or a panoramic source image orany portion thereof. Images may include virtually any type of digitizedgraphical content including photographs, pictures, sketches, paintings,etc. FIG. 5 shows a flow diagram for inter-scene motion creation 410according to an embodiment of the invention. Inter-scene motion creationmay include four components: camera pose estimation 500, transitionalobject creation 510, transitional parameter editing 520, and virtualcamera editing 530. Note that these steps need not be performedsequentially and one or more steps may be repeated as many times aredesired. Further, all steps may not need to be performed in eachinstance.

The first step 500—acquisition camera pose estimation—determinesrelative acquisition positions of the first and second scenes in 3Dspace (i.e., a world space). More technically, the pose estimation stepdetermines the camera extrinsics—the position and orientation of theacquisition camera. To simulate 3D motion from one point in space toanother, it is necessary to compute relative distances and orientationsof the source images with respect to each other. Typically, to computethe pair-wise pose estimation, correspondences between common featuresin the source images are established, automatically or with humanintervention. With appropriate levels of corresponded features, therelative camera extrinsics may be computed. In a specific embodiment ofthe invention, planar rectangular feature correspondences between thescenes are used to estimate the pose. In another specific embodiment ofthe invention, a perspective rectangle tool (“PRT”) is provided, asdescribed below, to facilitate tracing of rectangular features in animage. Note that this step established a transformation that maps thefirst scene into the second scene and that, in embodiments of theinvention, a variety of techniques, as are known in the art, may be usedto determine this transformation. Note that the source images may showthe same physical location or different physical locations and featureswithin the source images that are corresponded need not be the samefeature or at the same location.

Transitional objects are then created 510. Once the relative positionsof the first and second scenes are determined, then a path for a virtualcamera is selected from the first scene to the second scene. The camerapath may be any arbitrary path, but, by default, the camera path may bea straight line. To simulate motion, “transitional objects” are created.Transitional scenes incorporating these transitional objects aredisplayed to simulate motion from the first scene to the second scene.These transitional objects are typically objects in the transitionalscenes that are formed by combining a portion or feature of the firstscene and a portion or feature of a second scene. The combiningoperators are what we call transitional parameters, described in detailbelow. In a specific embodiment of the invention, three-dimensionalgeometry with projective texture mapping may be used to createtransitional objects. The projective textures are either from the firstsource image, or the second source image, or a blend of both. When thetransition to the second scene has been achieved, the transitionalscenes including the transitional objects disappear, and the user seesonly the second scene. For example, transitional objects in a beachscene may include people, beach umbrellas, the beach, and/or the sky. Asthe virtual camera travels to the second scene, the people, the beach,the sky and the umbrellas pass by to correctly simulate a 3D motion inspace.

Next, transitional parameters may be entered and adjusted 520. As thevirtual camera travels from the first scene to the second scene,transitional parameters determine how the transitional objects in thetransitional scenes vary in time, as the motion is simulated from thefirst scene to the second scene. Transitional parameters may includealpha blending (transparency), motion blurring, feature morphing, etc.In general, the transitional parameters may be thought as imageprocessing filters (both 2D and 3D) that are applied over time duringthe flight of a virtual camera along a path.

Finally, the virtual camera path from the first scene to the secondscene may be edited 530. In some embodiments of the invention, thevirtual camera path may be linear by default from the acquisition pointof the first scene to the acquisition point of the second scene.Alternatively, the virtual camera path may be determined to be anarbitrary path, e.g., a curved path. Further, the speed at which thepath is traversed may vary. Furthermore, the viewing direction may pointin any direction and may change during the transition from the firstscene to the second scene.

In an embodiment of the invention, a “perspective rectangle tool”(“PRT”), enables a user to draw “exact” rectangular features on a sourceimage (in perspective) using a constrained user interface. (By “exact,”we mean the measure of each corner angle of the rectangle is 90 degreesin a world plane.) FIG. 6 illustrates an acquisition position 600, asource image on the image plane 610, and a projection of a rectangularfeature onto a world plane 620. The source image on the image plane 610is what we may see as a part of a panorama on a computer display fromthe acquisition position 600. FIG. 7 shows a close-up of the image planeand the world plane. Shown on the image plane is a rectangular feature(a building façade) with perspective 700 in x and y coordinates, andshown on a world plane is a rectified building façade 710 in x′ and y′coordinates. Points 1-2-3-4 on the image plane 700 correspond to points1′-2′-3′-4′ on the world plane 710.

If we assume that the perspective rectangle on the image plane is anexact rectangle then we can compute a world plane where thecorresponding rectangle is an exact rectangle. We describe next anembodiment of the invention where constraints are applied to the userinterface such that the four points clicked on the image plane (via apointing device on the display surface) will always create an exactperspective rectangle, therefore, enabling a world plane to be defined,in which the corresponding rectangle is a rectified exact rectangle.

As shown in FIG. 8, the user first identifies three corners 800, 810,820 of the building façade with a pointing device. The user interfaceconstrains the user-identified fourth point to a solution curve 825. Theresulting four-sided polygon is always an exact perspective rectangle,i.e. always a perfect rectangle with 90-degree corner angles as seen onthe world plane. As the fourth point is moved, the user interfaceconstrains the edges 1-4 and 3-4, such that the resulting four-corneredpolygon in the image plane is maintained as a perspective rectangle. Inthe world plane, therefore, the four points correspond to a rectangle.In FIG. 8, points A and B on the solution curve (840 and 850,respectively) are also valid specifications of a perspective rectangle,but points A and B do not match the building facade of the source image.(PRT used as a feature correspondence tool between two source images isdiscussed below.).

Once the four corners of the rectangular feature have been established,any of the corners may be selected with a pointing device and edited.Similar constraints are applied such that any edits to the corner willmaintain the exactness of the rectangle. Edges may also be edited aswell while maintaining the exactness requirement. In a specificembodiment of the invention, as illustrated in FIG. 9, the user mayinteractively move one of the edges on the perspective rectangle (e.g.,900), and the edges will be constrained such that the polygon in theimage plane will transform into a rectangle in world space. Moving theedge in the image plane may be seen as constraining the edge to thevanishing points, 910 and 920; in the case of the illustrated example,the edge is constrained to 910. In other specific embodiments of theinvention, processes such as edge detection, corner detection, and thelike may be provided to facilitate feature selection.

A flow diagram of a process for determining a perspective rectangle isshown in FIG. 10. From points 1-2-3-4 of the perspective rectangle onthe image plane (1000, 1010, 1020, 1025), a pair of vanishing vectorsare derived (1030, 1035). Note that at this point, the user-specifiedpoint 1025 may not be on the solution curve. It is used to compute theclosest point on the solution curve that maintains the exactnessrequirement. On FIG. 11, the vanishing points created are shown 1100,1110 and, and the vanishing vectors, x 1120 and y 1130, are thencalculated (vanishing vector computation is described below). Note thatvanishing points only happen from the perspective of the camera. If thevectors are orthogonal, the perspective rectangle 1-2-3-4 defines arectangle and its plane in world space and the process completes 1070.If the vanishing vectors are not orthogonal, an edge is selected to bemoved to make the vectors orthogonal 1045, 1050. Once the edge to bemoved is selected, a point of the polygon is moved to make the vectorsorthogonal and the process completes 1070.

We now describe a 3D graphics-oriented technique to compute vanishingvectors (FIG. 12). First, from any default acquisition position, p 1230,create four points by drawing a line from p to the four corners of theperspective rectangle on the image plane, v₁, v₂, v₃, v₄. Moretechnically, the image plane is defined as a plane that is orthogonal tothe view direction from p, where p does not lie on the image plane, andthe image plane lies in the half space in the viewing direction. Notethat we also assume a pinhole camera is positioned at p, orientedtowards the view direction, and has set intrinsics (i.e. the propertiesof the camera, including field of view, the center of projection).Therefore, v₁, v₂, v₃, v₄ are the corners of the perspective rectangleprojected on to the image plane according to the camera intrinsics. Tocompute the vanishing vector x, we define two planes, one from threepoints p, v₂, v₃, and the other from three points p, v₁, v₄. Anintersection of these two planes, 1200 and 1210, creates a line 1220 onwhich the vanishing vector x lies. To determine the direction on theline toward which the vanishing vector x points, we use a consistentwinding order of the four points as specified by the user. The vanishingvector y may be computed similarly using planes p, v₁, v₂, and p, v₃,v₄.

In an embodiment of the invention, a corner (e.g. the fourth point) ismoved via a pointing device with a click-and-drag command. As the userpresses a button on the pointing device down, the fourth point isdetermined, and as the user drags around to determine where to place thefourth point, the vanishing vectors are computed and the edges 1-4 and3-4 are placed such that the exactness constraint is valid.

As shown in 1045 and 1050, while moving the fourth point, a “controledge” is determined by the user. A “control edge” in this case is eitheredge 3-4 or 1-4. In a specific embodiment of the invention, differentpointing device buttons are used to determine the control edge. Withoutloss of generality, if the control edge is defined as 3-4, then as thefourth point is moved using a pointing device, the control edge 3-4 isdefined by drawing a line from point 3 to the current position of thepointing device. Point 4, which is on the solution curve, lies somewhereon this line. Vanishing vector y may be defined using the mentionedtechnique above, the two planes being p, v₁, v₂, and p, v₃, m, where mis the current mouse position on the image plane. To compute theorthogonal vanishing vector x, two planes are again intersected, thefirst plane being p, v₂, v₃, and the second plane being the dual ofvector y. Each vector in 3D space has its dual: an orthogonal plane. Thecomputed x and y are guaranteed to be orthogonal. Finally, intersectingthe plane p, v₃, m with line defined by v₁+x computes the 3D position ofv₄. Projecting the 3D point v₄ onto the image plane provides the exactposition of point 4 while maintaining the exactness constraint.

In a specific embodiment of the invention, acquisition camera poseestimation may be computed by corresponding rectangular features in afirst scene and a second scene by using PRT. FIG. 13 shows the inputsource images, in this case two spherical panoramic images, 1300 and1310, with the rectangular features of a building façade outlined, 1320and 1330, respectively. In FIG. 14, the same facades 1400 and 1410 ofthe two input images are shown, as seen from a panorama viewer in theimage plane (e.g. the straight lines are straight and are in proportion)that correspond to 1320 and 1330, respectively. The respective facades1420 and 1430 are shown in a world plane view. Using PRT, thecorresponding four corners of the feature are corresponded in matchingorder. PRT guarantees 1420 and 1430 to be exact rectangles.

Once corresponding features have been selected, a solution for theextrinsics of the acquisition points (camera pose) relative to eachother may be computed. This solution involves maintaining the firstscene static while rotating and translating the second scene, so thatthe rectangular feature in the second scene matches in direction, sizeand placement the corresponding feature in the first scene. From theseoperations, the relative positions and orientations of the two scenes inworld space may be determined. Thus, the transformation mapping thefirst scene into the second scene using the rectangular features may bedetermined.

The rotation needed to align the second to the first scene is determinedfrom the normals of the respective world planes. PRT defines first andsecond world planes from the corresponding rectangular features, andeach plane has its dual, a normal. As discussed before, each rectangularfeature in the world plane provides a pair of parallel lines that meetat a vanishing point (via PRT). Similarly to FIG. 12, a pair ofvanishing vectors is determined from two orthogonal pair of parallellines of the PRT. This is done for both corresponding features. Asillustrated in FIG. 15, once the vanishing vectors, x and y, have beencomputed, 1500 and 1510, PRT guarantees orthogonality between x and y. Asimple cross product computes a vector, n, which is the normal vector ofthe world plane. Both normal vectors are computed, the first world planenormal and the second world plane normal, respectively. With the normalsof the two scenes determined, n₁ from the first scene's PRT feature andn₂ from the second scene's PRT, the second image may be rotated to alignthe direction of the two images by matching n₂ to n₁. By doing thisrotation step, we are aligning the world planes parallel to each other.

The translation step is a two-step process. The first step involvesreducing the translation solution space to a one-dimensional problem;and the second step then computes the solution in the one-dimensionalspace (FIGS. 16 and 17). To do this, we first place the rotated scenesin a common coordinate system, i.e., the “world space,” as shown in FIG.16. Initially, we assume that the acquisition positions for both scenesare the same point. The rectangular features, as seen from a commonviewpoint 1600, would seem to lie on the “same” plane (1610 and 1620),since their normals are the same in perspective—but the rectangles seemlike to be situated at different places and have different sizes.

Next, the centroid of each PRT rectangle is computed. To compute thecentroid, we first place the world planes at an arbitrary distance fromthe acquisition position. The four corners of the rectangle are thenprojected onto the plane. The four projected points, which are nowspecific points in 3D space, are averaged to compute the centroid. Thecentroid of the second PRT rectangle is then translated to match thecentroid of the first PRT rectangle. As shown in FIG. 16, the rectanglethat formerly was situated at 1620 is now translated to 1630. Thistranslation, 1640, is applied also to the acquisition position of thesecond scene, 1650. After this step, both world planes are coplanar andshare common centroids.

The line that goes through the centroid (now commonly shared point inspace) to the new position of the viewpoint for the second panoramaposition is the one-dimensional solution space 1660. We call this the“solution line.” Moving the second scene position along the solutionline means the projected rectangle on the common world plane changes insize, i.e., area. The final step, a translation along the solution line,is illustrated 1670. The second translation, 1670, matches the areas ofthe PRT rectangles in the world plane.

The exact solution is now computed by matching the area of the rectangleof the second panorama to that of the first panorama. FIG. 17illustrates the birds-eye view in detail of the translation 1670. Theinitial positions of the first scene and the second scene (right before1670) are defined by p_(s) 1700 and p_(d) 1730, respectively. The firstscene's position, p_(s), remains static while p_(d) is translated alongthe solution line, 1720. From the initial position p_(d) 1730, the newposition p_(d) 1710 along the solution space, 1720, is determined suchthat the areas of the rectangle are the same. As p_(d) 1730 gets closerto the centroid c, the area of the projected rectangle becomes smaller,and vice versa. Somewhere on the solution line lies the point 1710,where the areas of both projected rectangles are the same.

$\begin{matrix}{h_{d} = \sqrt{r_{d}^{2} + b_{d}^{2}}} & (1) \\{r_{d} = {\frac{\sqrt{A_{s}}}{\sqrt{A_{d}}}r_{s}}} & (2)\end{matrix}$

Computing the distance h_(d) determines the final translation position.Equation (1) shows the length of h_(d), where it is the hypotenuse of aright triangle, and r_(d) and b_(d) are opposite and adjacent sides,respectively. Equation (2) shows how to compute the orthogonal distanceto the normal plane r_(d), where A_(d) and A_(s) are areas of theprojected rectangles of second and first panoramas onto the world plane,respectively. By computing h_(d), we are computing the distance from cto p_(d), such that the projected areas of the first and second PRTrectangles are the same.

In another embodiment of the invention, multiple pairs of rectangles maybe corresponded to further improve the alignment. This is done by usingthe weighted average of each solution position of the second panoramapositions. There are two aspects of the user-specified rectangle toconsider: the angle and the size of the user-specified rectangles. Thefinal position of the second panorama is determined by:

$\begin{matrix}{\frac{\sum\limits_{i}^{k}{\sum\limits_{j}^{s,d}{\left( {n_{i,j} \cdot v_{i,j}} \right)A_{i,j}p_{i}}}}{\sum\limits_{i}^{k}{\sum\limits_{j}^{s,d}{\left( {n_{i,j} \cdot v_{i,j}} \right)A_{i,j}}}},} & (3)\end{matrix}$where k is the number of corresponded rectangle pairs, variable j is forsecond panorama and first panorama rectangles, n_(i,j) is the normal ofthe rectangle, v_(i,j) is the unit view vector from the acquisitionposition to the center of the rectangle (in 3D space), A_(i,j) is thesolid angle of the projected rectangle subtended on a unit sphere, andp_(i) is the solution position of the second panorama computed from ouralignment algorithm.

More intuitively, (n_(i,j)·v_(i,j)) considers the angle of the rectangleas seen from the acquisition position—the more grazing the angle, theless confidence that the user-specified rectangle is correct. The sizeof the rectangle is also considered, since with a larger relativerectangle, user errors are less likely.

In preferred embodiments of the invention, once the camera pose has beenestimated, transitional objects may then be modeled. As mentioned above,transitional objects are transient objects created for simulating motionfrom a first scene to a second scene.

In a specific embodiment of the invention, three-dimensional geometryand projective texture mapping may be used to create transitionalobjects, similar to those described in U.S. patent application Ser. No.10/780,500, entitled “Modeling and Editing Image Panoramas.” In suchtechniques, a single merged texture map is used for each geometry, wherethe respective texture may be created from a blend of multiple sourceimages. FIGS. 18-23 illustrate a sequence of steps for an embodiment ofthe invention, where 3D geometry is modeled and photo-textured using anextrusion tool.

In FIG. 18, three illustrations show different representations of thesame scene 1800, 1810, 1820, which is an interior room. 1800 illustratesan image-plane view (i.e., the view of the scene through a panoramaviewer). As shown, a pointing device is used to click and place a vertex1830 on the bottom corner of the displayed scene. Similarly, 1810 is atop-down view in 3D space, and 1820 is the axonometric view; both ofthese views show the acquisition position for the scene, 1840. Bothimage-plane and axonometric views (1810 and 1820) also show the pointingdevice, 1830. (Note that the user interaction occurs once, but is shownin each representation.) In FIG. 19, as shown in the threerepresentations 1900, the user clicks around and traces the footprint ofthe interior room. FIG. 20 shows a completed tracing of the footprint.The next step is the extrusion process, as shown in FIG. 21. Using thepointing device, the user extrudes (i.e., “raises”) the “walls” from thefootprint, until the walls meet the “ceiling” in the image-plane view(FIG. 22). Once the geometry has been created using the extrusion tool,the appropriate photo-textures may be copied and applied projectivelyfrom the source image (e.g. a panorama) to the newly created geometry.(See, for example, Mark Segal, et al. “Fast shadows and lighting effectsusing texture mapping”. In Proceedings of SIGGRAPH 92, pages 249-252).In other embodiments of the invention, other geometry creation tools, asare known in the art, may be coupled with projective texture mapping tocreate photorealistic content.

In a specific embodiment of the invention, two textures may be storedfor each geometry (or geometric element)—one texture from the firstscene, and the other texture from the second scene. During thetransition from the first scene to the second scene, these textures mayalso transition—i.e., alpha blending (i.e. transparency), morphing,motion blurring, and other types of image processing may be applied tothe scenes, according to transitional parameters. (Transitionalparameters are discussed in detail below.)

FIGS. 23-25 show a transitional object creation tool for a specificembodiment of the invention. In FIG. 23, a first scene 2300, and asecond scene 2310, which are room interiors, are shown with acquisitionpositions of the two scenes 2320, 2330. The footprint of the interior ofboth first and second scenes (2300 and 2310, respectively) are modeledas shown in FIG. 23, according to the extrusion process described abovein connection with FIGS. 18-22. These scenes are for two viewpoints ofthe same world space. Pose estimation may be accomplished, as describedabove or according to another technique, as is known in the art. Theuser can point to on either side of the display window to trace thegeometry of the transitional objects. Note that the photo-texture oneach footprint as seen from a top-down view is naturally “stretched”from the acquisition position, since projective texture mapping isemployed.

FIG. 24 shows the two scenes as seen from the acquisition positions.Both scenes are viewed in a similar direction, i.e., toward the entrancedoors of the room, and the traced footprint is visible in both scenes2400, 2410. The extrusion direction 2420 is shown by the arrow, wherethe walls are extruded from the footprint. It is, again, important tonote that the modeling may be done simultaneously for both scenes—thewalls, floor and ceilings that are extruded may be automaticallycorresponded between the first and the second scene, as shown in FIG.25. FIG. 25 shows several examples of automatic transitional objectcorrespondences 2520, 2530, and 2540. FIG. 26 shows the two scenes froma third-person's viewpoint, which is now possible with the createdgeometry overlaid with projective texture maps from each scene. FIG. 26includes the familiar “lollipop” icons 2600, 2610 that signify theacquisition positions relative to the created geometry, and thecorresponding transitional objects 2620, 2630, 2640, 2650 are alsoshown.

The transitional object modeling tool may also be used for non-planargeometries. Various 3D primitives, such as cubes, spheres, cylinders,may also be modeled. Also, triangle meshes and analytical geometricdescriptions may also be modeled coupled with projective texturemapping. Furthermore, transitional objects that do not havecorresponding views may also be modeled (as is described below).Oftentimes, due to the complexity of scenes, each feature may not bevisible in both scenes. In this case, the geometry may still be modeled,but there may only be a single texture, either from the first scene orfrom the second scene.

In a preferred embodiment of the invention, the transition from thefirst to the second scene is modeled using a “virtual camera.” As shownin FIG. 27, once the relative camera pose has been computed, and thetransitional objects created, we can now transition from the first scene2700 to the second scene 2710. Note that although the geometry is thesame in this case, the projective textures are different—2700 is thescene as seen from the first scene 2720, and 2710 is the scene as seenfrom the second scene 2730. The virtual camera path 2740 is linear bydefault. However, the camera path can be any curve, as described below.

FIG. 28 shows the points along the virtual camera's path as a transitionis made from the first scene to the second scene (2830, 2840, 2850).Alpha blending the first and second scenes is used to illustrate theprogression of transitional objects according to a transitionalparameter, the degree of alpha-blending. When the virtual camera is 25%down the path (2800), the alpha blending transitional parameter is setat 75% from the first scene and 25% from the second scene. In 2810, theparameter is set at 50%-50%; and in 2820, the parameter is set 25%-75%.As will be discussed below, transitional parameters change as thevirtual camera transitions from the first scene from the second scene.Thus, the transitional scenes displayed during the transition changeaccordingly. FIG. 29 shows the point of view from the virtual camera.2900 corresponds to the virtual camera at the first scene, 2910 is 25%down the path, 2920 is 50% down the path, 2930 is 75% down the path, and2940 corresponds to the virtual camera at the second scene.

FIG. 30 shows the transition sequence for a different transitionalobject. 3000, 3010, 3020, 3030, 3040 are sequences corresponding to awall geometry and textures that are behind the viewpoint of FIG. 29. Thetransitions of transitional objects occur regardless of where thedirection in which the virtual camera is pointed. This means that thevirtual camera can be looking in any direction (even behind) as ittransitions along the path. Furthermore, the next set of transitionsthat may happen could be from the second scene back to the first scene,in which case, much of the existing transitional objects may be reused.

In a specific embodiment of the invention, a user interface provides forinteractive editing of transitional parameters. FIG. 31 shows the layoutof an illustrative transitional parameter editor (“TPE”), according toan embodiment of the invention. 3100 shows the main display, which is aninteractive panorama viewer in this instance, and a transitional objectdisplay list 3110. The user can navigate the 3D environment thatcontains the transitional objects interactively in a WYSIWYG fashion(“what you see is what you get”). The transitional object list displaysthe created transitional objects, and may be used for togglingselection, visibility, and other parameters. The bottom window pane 3120shows transitional parameter graphs. These graphs show the parametervalue at any point along a path for the virtual camera.

FIG. 32 shows a close up view of a TPE screen. As shown, transitionalparameters are represented by 2D graphs 3200, 3210, and 3220. Theseparameters may correspond to alpha-blending, motion blurring, colorsaturation, morphing, etc. The horizontal axis is the time, where“time=0.0” represents the start time and “time=1.0” is the end time,during which the virtual camera moves along the predefined path from thefirst scene 3230 to the second scene 3250. The range may be a normalizedrange and the user can separately change the speed and acceleration ofthe camera at various points on the path. The vertical axis for eachtransitional parameter depends on the parameter. For instance, for alphablending, the vertical axis ranges also from [0.0, 1.0], where 1.0 iswhen the transitional objects from the first scene are completely opaqueand the transitional objects from the second scene are completelytransparent, and 0.0 is the inverse. The graphical user interface isprovided for the user to interactively and graphically adjust eachparameter using a 2D curve 3270. The timeline slider, as shown on thevertical bar 3260, can be interactively dragged left or right to previewthe transitional image that is displayed on the main display 3100. These“transitional images” rendered on the main display reflect what thevirtual camera would see and how the transitional parameters affect thetransition (again, WYSIWYG). FIG. 33 shows a close-up of a generictransitional parameter graph. The timeline slider 3310 that may beinteractively dragged left or right, respectively moving forward orbackward in time, is shown. The 2D curve 3300 on the transitionalparameter graph specifies the value of the transitional parameter at agiven time in the virtual camera's flight along a path. Vertices may beadded, deleted and modified to change a transitional parameter at agiven time.

In specific embodiments of the invention, transitional parameters mayinclude: alpha blending, motion blurring, morphing, saturation change,camera speed, and camera XY-offset factors. Other transitionalparameters may be defined as desired. In general, any type of imageprocessing filter or algorithm for both 2D and 3D may be applied to thetransitional images, and transitional parameters may be entered tocontrol the filters or algorithms as a function of time (or position)along the path. FIG. 34 shows some effects of two transitionalparameters: motion blurring and saturation adjustment. By applying acombination of transitional parameters, including alpha blending, motionblurring, morphing, etc., over time, a visually convincing simulation ofmovement between two scenes (images or panoramas) can be provided.

An intermediate image (or images) taken between two scenes (images orpanoramas) may be used as a further source image in conjunction withthese alpha blending, motion blurring, morphing, etc. techniques toimprove the appearance of a transition between a first scene and asecond scene. For example, on the path between a first panorama and asecond panorama, there may be several ordinary images (i.e., images thatare not necessarily panoramic) available. These images can be used asintermediate points for the alpha blending, motion blurring, morphing,etc., to create an even more visually convincing transition between thetwo panoramas.

Morphing for a transitional object requires additional featurecorrespondences as compared to other techniques, such as alpha-blending,motion blurring, etc. FIG. 35, illustrates the features of atransitional object where morphing is employed, according to anembodiment of the invention. For each pair of projective texture mapsthat have been defined from creating the transitional object, the usercan apply corresponding features. FIG. 35 shows the correspondingtransitional object 3500, 3510 as seen from the first scene (left) andthe second scene (right). The user can interactively point to the imageto correspond features using points, lines, polylines, loops, etc, andthe texture and geometry are then triangulated according to theadditional features. (See, for example, Thaddeus Beier and Shawn Neely,“Feature-based Image Metamorphosis,” In Proceedings of SIGGRAPH 1992,pages 35-42) Using the TPE's 2D graph for the morph transitionalparameter, the user can then control the speed at which the morphingoccurs from the first scene to the second scene interactively (bothforward and backward in time). FIG. 36 shows two instances of a morphingtransitional object and its triangulated geometry according to theuser-specified morph features. 3600 shows the initial time step (thetimeline slider at time=0.0), and 3610 shows when time=0.5. As thetimeline slider is moved or automatically played, the morphing graduallyoccurs from the first scene to the second scene, transitioning both thetexture as well as the corresponding geometry (in this case, a trianglemesh). FIG. 37 shows an example where morphing may be useful to minimizevisual artifacts in the transition from the first scene to the secondscene. 3730 shows a close-up of a transitional object when displayedwithout morph features—there are “ghosting” affects that make the textillegible. The ghosting artifact may arise, for example, from errors inpose estimation or in feature correspondence. Morphing can substantiallyfix many of the ghosting issues. 3700 and 3710 show rectified buildingfaçade textures from the first scene and the second scene, respectively;3720 and 3725 are some morph corresponding features; and image 3740shows the hotel name transitional object without the ghosting artifacts.

Examples of inter-scene transitions created with embodiments of thepresent invention are shown below for a variety of scene types. Theseexamples show the importance of transitional parameters to alleviate thenecessity of precision in pose estimation for traditional vision andcomputer graphics problems.

FIGS. 38-39 show a long-distance transition, where the first and secondscenes do not share obvious features. FIG. 38 shows the two panoramas,as the first scene 3800, and as the second scene 3810. 3820 points tothe position of the second scene panorama as shown in the first scenepanorama; and 3830 points to the position of the first panorama as seenin the second scene panorama. As shown, although large features, such asbuildings in the background, are visible, the actual pedestrian-scaledobjects around both scenes are not visible from each other. FIG. 39shows a sequence of frames (i.e., “transitional images”) as the virtualcamera moves from the first scene to the second scene (3900, 3910, 3920,3930, 3940, and 3950). Circles in each frame signify the position of thesecond scene. To estimate the pose (camera extrinsics), the largefeatures, such as the buildings were used. Although the resulting poseestimation computation did not guarantee high precision, a credibletransition was still modeled. Applying various amounts of 3D motionblurring also helped minimize visual artifacts.

The next example is of two scenes that do not have exact features tocorrespond. FIG. 40 shows the first and second scene panoramas, 4000 and4010. 4020 and 4030 shows a closed doorway through which the virtualcamera will pass during the transition, i.e., the first and secondscenes are on opposite sides of the door. For this example, the door wasused as an approximate feature to correspond between the first scene andthe second scene. FIG. 41 shows the 3D transitional objects that havebeen created and the first scene and second scene acquisition positions,4100 and 4110 respectively. FIG. 42 shows the sequence of transitionalimages, 4200, 4210, 4220, and 4230. As shown, a smooth transition iscreated. The artist who created this transition also made the doorwaytransparent as the virtual camera passed through. Even with mirroringfeatures (the door) used for estimating the pose, and none of thetransitional objects having correspondences, the TPE's unique graphicalinterface enabled the artist to use the timeline slider and transitionalparameter values to convincingly create this transition.

The final example is shown in FIGS. 43 and 44. The first scene 4300 hasits acquisition point 4320 as shown and the second scene 4310 has itsacquisition point 4330 as shown. In this example, there were almost norectangular features for PRT correspondence, but the artist was able toadequately approximate the positions, as shown in 4420 as a bird's eyeview of the transitional objects. With adequate transitional parameteradjustment, smooth and believable motion between scenes was created.

In embodiments of the invention, once the inter-scene motion has beencreated, the scenes may be populated with artificial entities thatinteract with the user—called “active elements.” Typically, activeelements are activated through a pointing device. Other methods ofactive element activation are described below.

As shown in FIG. 45, there are three components to active elementcreation: perspective plane selection 4500, creating and/or importingactive elements 4510, and connecting the active elements to theirbehavior when activated 4520.

One of the most important active elements is called a “navigationalicon.” A navigational icon activates motion within scenes, such as froma first scene to a second scene. As shown in FIG. 46, the viewer 4600shows one form of navigational icon 4610. In this embodiment of theinvention, the navigational icon is purposely colorful (although notvisible in the black and white image) and small, so that the icon isvisible but does not obstruct the visibility of the scene. Also, in aspecific embodiment of the invention, as the user pans around thepanorama, the navigational icon remains “sticky” to the environment, andtherefore, pans along with the environment. As shown in 4620 and 4630,once the navigational icon is activated, the action enabled is themotion between the first scene and the second scene.

Navigational icons can play an important role in viewing scenes,enabling the user to visually understand that once a navigational iconis activated, inter-scene motion is triggered. This consistency in“visual language” is an important concept, especially in virtualenvironments. Furthermore, the navigational icon now enables a complexnetwork of inter-scene motions, not only between two scenes in aone-directional way, but potentially among thousands of scenesinterconnected multiply-directionally. An example of such a “supertour”at a city-scaled inter-scene connection is shown below.

FIG. 47 shows an example of other types of active elements embedded intoscenes. 4700 shows the “before”, and 4710 shows the “after.” In aspecific embodiment of the invention, these active elements may beactivated via a pointing device triggering web sites to appear withappropriate and related information. For instance, clicking on 4720,which is a “private events” advertisement above a hotel's receptionarea, will open up the hotel's website that contains private-eventrelated information. Other active elements can be embedded in a“natural” manner. As the user pans around a scene panorama, theseembedded active elements can also remain “sticky” to the environment.

Active elements are inserted into the scene with correct perspectives.This is done via an embodiment of the invention called the “ActiveElement Creator” (“AEC”) that enables the user to determine existingplanar perspectives in the scene, and then create and edit layers ofinformation into the scene. FIGS. 48-52 illustrate AEC. FIG. 48 showsthe AEC user interface for determining a planar perspective, and thenintuitively adding other visual layers to it. 4800 is the panoramaviewing window—what we call an “image-plane view.” 4810 is the“world-plane view” window (without an image yet in FIG. 48). Once aplane has been defined using the Perspective Rectangle Tool (“PRT”), arectified image of the scene is shown. (See description of PRT above).Due to the interactive and projective nature of the panorama and itsviewer, perspectives of the features in the scene continuously change asthe user interactively pans around to view various directions in thescene. AEC enables the user to create sticky and perspective-correctedactive elements embedded in the scene.

In FIG. 48, 4830 shows three points of a rectangle selected by the userto define a perspective rectangle using PRT. FIG. 49 shows the definedplane via PRT on the image-plane view on the left 4900, and theworld-plane view on the right. 4910. Note that 4910 is a rectified viewof the perspective plane defined in 4900. Once the world plane has beendefined, it is easier to annotate, add visual layers, and modify,similar to two-dimensional drawing and image editing software. FIGS.50-52 show how two-dimensional figures, text, images are added into theworld-plane view, and reflected immediately on the panoramic scene onthe left. These active elements may be then hyperlinked to web pages,applications, documents, etc.

Note that defining image-plane and world-plane rectangles thatcorrespond to each other does not only create rectangles, but alsocreate a one-to-one mapping between the two coordinate systems, x-y andx′-y′ (FIG. 7) Therefore, editing and adding text or drawings or imagesin one coordinate system can be simply mapped to the other coordinatesystem. A 3×3 matrix, H, called the “homography” is defined, that maps apoint in image plane to a corresponding point in world plane. (See, forexample, J. G. Semple and G. T. Kneebone, “Algebraic ProjectiveGeometry.” Oxford University Press, 1952) Therefore, xH=x′, and x′H⁻¹=x.

FIGS. 53-54 show other examples of active elements, according tospecific embodiments of the invention. In FIG. 53, one active element5300 is shown that may be called a “hotel banner,” where the name andother information regard the hotel is embedded into the scene as anactive element. Clicking on a hotel banner triggers actions that open upweb pages with relevant information regarding the hotel. In FIG. 54,5400 is what we call a “virtual kiosk,” that contains relevantinformation about a specific scene. It is a scene-specific informationalicon. In this example, the virtual kiosk contains information about thebeach and various activities.

In embodiments of the invention, a supertour is created including acomplex network of scenes, inter-scene motions, active elements, andoverview maps. FIG. 55 shows the overview flow diagram (see FIG. 4), anda flow diagram for the steps creating a supertour: importing the scenes5500, the inter-scene motions 5510, active elements 5520, and overviewmaps 5530, according to a preferred embodiment of the invention. The“scenes,” as mentioned before, are the source images, comprisingpanoramas and images. The “inter-scene motions” comprise transitionalobjects, transitional parameters, and a virtual camera that produces thetransitional images. Transitional images include one or moretransitional scenes that include a transitional object or objects. Theactive elements trigger specified actions, such as triggering aninter-scene motion via a navigational icon or display of amplifyinginformation about a scene. Finally, there are overview maps to aid in anoverall sense of position within an area. Overview maps are discussedfurther below.

In some embodiments of the invention, a scene viewer, which showsperspective images or panoramas, is coupled with an overview map viewer.As shown in FIG. 56, the scene viewer is on the right 5600 and theoverview map viewer is on the left 5610. The overview map shows a“bird's eye view” of the supertour. In a specific embodiment of theinvention, navigational icons 5620 are placed for each acquisitionposition where the panoramas have been photographed. Because thenavigational icons are a type of active element, activating thenavigational icon via a pointing device triggers the scene viewer tonavigate to that specific scene within the supertour, similar totriggering the active elements within the panorama viewer. The overviewmap viewer also moves and recenters automatically, synchronized with thescene viewer. 5630 is the “current” navigational icon which has aspecial highlight and an arrow that denotes the direction of the currentview in the scene viewer 5600. As the user interactively changes viewdirections in the scene viewer, the arrow changes directionsaccordingly. As the viewer position moves in the supertour, the currentnavigational icon is also synchronized accordingly.

In various embodiments of the invention, a method provides a means to“script” a series of scenes and transitions to play in sequence. In asupertour, a user typically invokes a transition from one scene toanother by activating a navigational icon using a pointing device.Scripting may be thought of as a means to “record” a supertour paththrough multiple scenes and their corresponding inter-scene motions, and“play” the pre-determined path once invoked by the user. The scriptedpath may be a user-recorded path, or may be algorithmically determined,e.g. a shortest driving direction between two points in a city,according to specific embodiments of the invention. This is differentfrom using additional source images to create a transition; scripts maybe dynamically customized on the fly.

For instance, assuming scenes “A” through “Z” exist in the supertour.Scene “A” is connected to “Z” only via intermediate scenes(corresponding to intermediate locations), “B” through “Y.” If thecurrent scene is “A,” and when a user selects a navigational icon “Z” onthe overview map, a script may be triggered that plays the scenes andthe inter-scene motions from “A” through to “Z” automatically andsequentially, such that the user may have a continuous and connectedexperience.

In specific embodiments of the invention, for the automatic playingnecessary for scripting, as well as for simple navigation throughnavigational icons, scene viewers provide, what we call, an “orientationmatching.” The scene viewer automatically aligns itself to the startingorientation of its connected inter-scene motion. For example, whiletraversing from scene “A” to scene “Z,” the user comes to anintersection scene, where a turn is necessary. The orientation matchingfeature automatically turns the viewer to align to the next inter-scenemotion, and then triggers the transition.

Also, in embodiments of the invention, at each given panoramic scene,the user can interactively change the viewing orientation using apointing device. To smoothly and seamlessly transition from one scene toanother, it is preferable that the user's viewing orientation firstmatch the beginning of the transitional image, and then initiate thetransition from the first to the second scene. This feature isespecially useful for transitional images in the form of pre-renderedmovies, since the panorama viewing orientation should be aligned to thefirst frame of the transitional movie to provide a seamless experienceto the end user.

In an embodiment of the invention, a data structure is implemented foreach pair of connected source images and their respective directionaltransitional image, where the orientation angles (θ,φ)₁ are the zenithand azimuth angles of the first scene, and the orientation angles (θ,φ)₂are the zenith and azimuth angles of the second scene that match thefirst and last frames of the transitional image, respectively. Theseorientation-matching data are stored during the inter-scene motionauthoring process. In accordance with an embodiment of the invention,the transitional images are created in a three-dimensional system, so itis easy to determine the exact view orientation of the virtual cameraalong the transitional image's path.

In an embodiment of the invention, once a transition from the firstscene to the second scene has been triggered, e.g., via a navigationalicon, a panorama viewer is provided that automatically reorients theview of the first scene from any given arbitrary viewpoint (θ′,φ′)₁ tomatch (θ,φ)₁ via interpolation of the view angles. Once (θ′,φ′)₁=(θ,φ)₁then the viewer renders the transitional image to simulate smooth motionto the second scene. Once reaching the second scene, the viewertransitions from displaying the transitional image to the second scene'spanorama, which is oriented such that the viewing angle (θ,φ)₂ for asmooth and seamless transition.

FIGS. 57-58 are an example that shows scripting as well as orientationmatching. In FIG. 57, the overview map is on the left 5700, and thescene viewer is on the right 5710. The scene viewer is showing a doorwaythat eventually leads to a bathroom after a right hand turn. Thebathroom is not visible from the current scene viewer, but the bathroomis shown in the overview map 5700. 5720 is a navigational iconsignifying the current position of the scene; 5730 shows a curved paththat will lead into the bathroom through an intermediate scene (viascripting); and 5740 is the final destination scene denoted by thenavigational icon.

FIG. 58 shows the sequence of events that happen (5800, 5810, 5820,5830, 5840, and 5850). 5800 is the initial view, which is the same asFIG. 57. Once the navigational icon (or some other means) triggers thetransition, the intermediate transition is shown 5810. Note also thatthe overview map displays the “current” position and direction using thepointing icon (same as 5720). Once reaching the intermediate scene 5820,the automatic orientation-matching feature is triggered, such that theintermediate scene viewer is aligned with the next transitional image5830. 5840 shows the actual transition from the intermediate to thefinal scene, 5850.

In these examples, it may seem as though all the scenes are connected toeach other in an “absolute” sense. In other words, the multiple scenesdisplayed on the overview map and the scene viewer may seem like theyare all positioned correctly with each other's position and orientationin world space. In embodiments of the present invention, supertours arecreated using only relative pose estimation between pairs of sourceimages. This approach contrasts with many vision research andimage-based modeling systems, in which it is important to compute asprecise a pose estimation as possible via feature correspondences amongsource images. This is a complex optimization problem, and is moredifficult and error-prone as the number of source images increases.

For example, in a simple scenario, assume there are three input sourceimages, A, B, and C, that share corresponding features, e.g. thephotographs are taken around a building; and each pair share commonfeatures, e.g. A-with-B, B-with-C, and C-with-A. Typical vision systemscompute the camera pose of B relative to A, then compute the camera poseof C relative to B, etc. The computation error from A-to-B poseestimation would naturally propagate to the pose estimation of B-to-C,since all source images reside in the same “absolute” coordinate system.If there are feature correspondences between C and A, then it isnecessary to have a global optimization algorithm to “spread” and lessenthe error propagation. Note that due to A-to-B and B-to-C poseestimation, A and C already have their positions set in an absolutecoordinate system. Trying to then compute the pose of A from C willnaturally create more pose estimation errors. In more complex scenarios,e.g. real-world data, a system of complex optimization problem is adifficult problem to solve, often has problems with robustness, and oncean error is introduced, it is difficult to “debug.”

In embodiments of the present invention, supertours are created usingrelative pose estimation only between pairs of source images. In otherwords, pose estimation for each pair of source images resides inrelative coordinate systems. There is no need for global optimization,since the pose estimation problem is determined for each pair of sourceimages. For the simplistic scenario of input source images A, B, and C,supertour only requires approximate pose estimations between A-to-B,B-to-C, and C-to-A, all of which are computed separately regardless ofthe error in each computation. This embodiment allows the user tosmoothly and continuously “move” from one source image to another.Therefore, from the viewpoint of scene A, the inter-scene transitionsimulates motion from A-to-B, and then ends up in scene B. Once reachingscene B, the coordinate system may change (which is seamless to theuser). Then simulating motion from B-to-C may be performed separatelyfrom pose estimation of A-to-B, regardless of its computation errors.This approach advantageously reduces computing complexity andopportunities for errors, allowing supertour embodiments to scale upmore easily as the number of nodes increase.

In preferred embodiments of the invention, the final process as shown inthe overview flow diagram (FIG. 4) is the publication step. Once thesupertour has been created that contains multiple scenes that areconnected via inter-scene motions, and also have active elements, thenthe supertour may be published, either as a stand-alone application 5910or delivered via the World Wide Web 5900 or any other communicationsystems as is known in the art. The published tour may also containadditional hyperlinks, images, text, etc. as necessary 5920, 5930.

FIG. 60 shows an exemplary embodiment of the invention where thepublication of supertour is made possible. It only shows a small sliceof a supertour 6000. As shown in the map interface in 6000, there areover a thousand panoramic scenes covering Miami Beach, Fla. 6010 showsan enlargement of the map. Each of these panoramic scenes isinter-connected in this supertour. Furthermore, the exterior scenes arealso inter-connected to the interior tours of buildings and hotels. Thecomplexity of a published supertour, for an exemplary embodiment, isshown in FIGS. 61-70.

In various embodiments of the invention, a method provides a transition,in a computer system having a display that simulates motion between afirst scene and a second scene. The method includes receiving anindication of a viewpoint in the second scene towards which a transitionis to be made. The indication may be received from a variety of sources.For example, the indication may be produced by entering searchparameters into a search engine and the search engine may identify thelocation. The indication may be received upon activation of an iconanywhere on the display—the icon need not be located on a plan view mapor a panorama viewer. When the location is received, a transitionalimage or a series of such images are displayed simulating motion towardthe location. In a further example, a list of locations may be presentedon the screen and the indication is received based on selection of anitem in the list as shown in FIG. 71.

Any of the above described embodiments of the invention may beimplemented in a system that includes a computer or other type ofprocessor. The computer or processor includes memory for instructionsimplementing the method steps. The computer or processor is coupled to adisplay device for displaying output and may be coupled to one or moreinput devices for receiving input from users. Instructions implementingthe method may be executed on a single processor or multiple processors.Processors may be organized in a client-server fashion. Multipleprocessors may be connected by public or private communication systemsof any type known in the art. Such communication systems may include,without limitation, data networks as are known in the art, such as theinternet, using both wired and wireless link-level and physical media,point-to-point communication means, such as the public telephone system,satellite links, a Ti line, a microwave link, a wire line or a radiolink, etc. Display devices used in the system may be of any typesuitable for providing graphical displays. Displays may be directed fromany processor to any display surface and multiple display surfaces maybe employed in embodiments of the invention. Input devices for receivinginputs from users may take diverse forms including, without limitation,a keyboard, a pointing device, such as a trackball or mouse or touchpad,etc.

Systems according to embodiments of the invention may be described bythe following clauses:

A system for creating a transition between a first scene and a secondscene simulating motion, the first scene observed from a first viewpointand including a first feature, and the second scene observed from asecond viewpoint and including a second feature, the system comprising:a computer including a processor, memory and a display, the memorycontaining instructions that cause the computer to:

-   -   graphically identify on the display the first feature and the        second feature and determine a transformation mapping the first        scene into the second scene using the first feature and the        second feature; and    -   provide a transitional image that includes at least one        transitional scene based on the first feature and on the second        feature, such that there is simulated motion from the first        scene to the second scene.        A system for creating a transition between a first scene and a        second scene simulating motion, the first scene observed from a        first viewpoint and including a first feature, and the second        scene observed from a second viewpoint and including a second        feature, the system comprising: a computer including a        processor, memory and a display, the memory containing        instructions that cause the computer to:    -   display a first navigational icon embedded in the first scene;        and    -   when the first navigational icon is activated, display a        transitional image that includes at least one transitional scene        based on the first feature and on the second feature, such that        there is simulated motion from the first scene to the second        scene.        A system for creating a transition between a first scene and a        selected scene simulating motion, the first scene observed from        a first viewpoint and including a first feature, and the        selected scene observed from a selected scene viewpoint and        including a selected scene feature, the system comprising: a        computer including a processor, memory and a display, the memory        containing instructions that cause the computer to display the        first scene;    -   receive an indication of the location of the selected scene        viewpoint; and    -   when the indication of the location of the selected scene        viewpoint is received, display a transitional image that        includes at least one transitional scene based on the first        feature and on the selected scene feature, such that there is        simulated motion from the first scene to the selected scene.        A system for creating a first transition between a first scene        and a second scene and a second transition between the second        scene and a third scene simulating motion, the first scene        observed from a first viewpoint and including a first feature,        the second scene observed from a second viewpoint and including        a second feature, the third scene observed from a third        viewpoint and including a third feature, the system comprising:        a computer including a processor, memory and a display, the        memory containing instructions that cause the computer to    -   provide a first transitional image that includes at least one        transitional scene based on the first feature and on the second        feature, such that there is simulated motion from the first        scene to the second scene; and    -   provide a second transitional image that includes at least one        transitional scene based on the second feature and on the third        feature, such that there is simulated motion from the second        viewpoint to the third viewpoint,    -   such that the first transitional image and the second        transitional image are formed without determining the absolute        positions and orientations in a frame of reference of each of        the first, second and third scenes.        A system for creating a transition between a first scene and a        selected scene simulating motion, the first scene observed from        a first viewpoint and including a first feature, and the        selected scene observed from a selected scene viewpoint and        including a selected scene feature, the system comprising: a        computer including a processor, memory and a display, the memory        containing instructions that cause the computer to:    -   display the first scene;    -   receive an indication of the location of the selected scene        viewpoint;    -   determine a route from the first viewpoint to the selected scene        viewpoint, the route including the second viewpoint; and    -   when the indication of the location of the selected scene        viewpoint is received, display a transitional image that        includes at least one transitional scene based on the first        feature and on the second feature, such that there is simulated        motion from the first scene to the second scene.        Additional system embodiments of the invention may be described        according to the below listed method claims by adding additional        steps for the processor to execute.

Computer program products according to embodiments of the invention maybe described by the following clauses:

A computer program product for use on a computer system for creating atransition between a first scene and a second scene simulating motion,the first scene observed from a first viewpoint and including a firstfeature, and the second scene observed from a second viewpoint andincluding a second feature, the computer program product comprising acomputer usable medium having computer readable program code thereon,the computer readable program code including program code for:

-   -   graphically identifying on the display the first feature and the        second feature and determining a transformation mapping the        first scene into the second scene using the first feature and        the second feature; and    -   providing a transitional image that includes at least one        transitional scene based on the first feature and on the second        feature, such that there is simulated motion from the first        scene to the second scene.        A computer program product for use on a computer system for        creating a transition between a first scene and a second scene        simulating motion, the first scene observed from a first        viewpoint and including a first feature, and the second scene        observed from a second viewpoint and including a second feature,        the computer program product comprising a computer usable medium        having computer readable program code thereon, the computer        readable program code including program code for:    -   displaying a first navigational icon embedded in the first        scene; and    -   when the first navigational icon is activated, displaying a        transitional image that includes at least one transitional scene        based on the first feature and on the second feature, such that        there is simulated motion from the first scene to the second        scene.        A computer program product for use on a computer system for        creating a transition between a first scene and a selected scene        simulating motion, the first scene observed from a first        viewpoint and including a first feature, and the selected scene        observed from a selected scene viewpoint and including a        selected scene feature, the computer program product comprising        a computer usable medium having computer readable program code        thereon, the computer readable program code including program        code for:    -   displaying the first scene;    -   receiving an indication of the location of the selected scene        viewpoint; and    -   when the indication of the location of the selected scene        viewpoint is received, displaying a transitional image that        includes at least one transitional scene based on the first        feature and on the selected scene feature, such that there is        simulated motion from the first scene to the selected scene.        A computer program product for use on a computer system for        creating a first transition between a first scene and a second        scene and a second transition between the second scene and a        third scene simulating motion, the first scene observed from a        first viewpoint and including a first feature, the second scene        observed from a second viewpoint and including a second feature,        the third scene observed from a third viewpoint and including a        third feature, the computer program product comprising a        computer usable medium having computer readable program code        thereon, the computer readable program code including program        code for:    -   providing a first transitional image that includes at least one        transitional scene based on the first feature and on the second        feature, such that there is simulated motion from the first        scene to the second scene; and    -   providing a second transitional image that includes at least one        transitional scene based on the second feature and on the third        feature, such that there is simulated to motion from the second        viewpoint to the third viewpoint,    -   such that the first transitional image and the second        transitional image are formed without determining the absolute        positions and orientations in a frame of reference of each of        the first, second and third scenes.        A computer program product for use on a computer system for        creating a transition between a first scene and a selected scene        simulating motion, the first scene observed from a first        viewpoint and including a first feature, and the selected scene        observed from a selected scene viewpoint and including a        selected scene feature, the computer program product comprising        a computer usable medium having computer readable program code        thereon, the computer readable program code including program        code for:    -   displaying the first scene;    -   receiving an indication of the location of the selected scene        viewpoint;    -   determining a route from the first viewpoint to the selected        scene viewpoint, the route including the second viewpoint; and    -   when the indication of the location of the selected scene        viewpoint is received, displaying a transitional image that        includes at least one transitional scene based on the first        feature and on the second feature, such that there is simulated        motion from the first scene to the second scene.

Additional computer program product embodiments of the invention may bedescribed by adding program code steps according to the below listedmethod claims for the processor to execute.

Computer program logic implementing all or part of the functionalitypreviously described herein may be embodied in various forms, including,but in no way limited to, a source code form, a computer executableform, and various intermediate forms (e.g., forms generated by anassembler, compiler, networker, or locator.) Source code may include aseries of computer program instructions implemented in any of variousprogramming languages (e.g., an object code, an assembly language, or ahigh-level language such as Fortran, C, C++, JAVA, or HTML) for use withvarious operating systems or operating environments. The source code maydefine and use various data structures and communication messages. Thesource code may be in a computer executable form (e.g., via aninterpreter), or the source code may be converted (e.g., via atranslator, assembler, or compiler) into a computer executable form.

The computer program may be fixed in any form (e.g., source code form,computer executable form, or an intermediate form) either permanently ortransitorily in a tangible storage medium, such as a semiconductormemory device (e.g., a RAM, ROM, PROM, EEPROM, or Flash-ProgrammableRAM), a magnetic memory device (e.g., a diskette or fixed disk), anoptical memory device (e.g., a CD-ROM), a PC card (e.g., PCMCIA card),or other memory device. The computer program may be fixed in any form ina signal that is transmittable to a computer using any of variouscommunication technologies, including, but in no way limited to, analogtechnologies, digital technologies, optical technologies, wirelesstechnologies, networking technologies, and internetworking technologies.The computer program may be distributed in any form as a removablestorage medium with accompanying printed or electronic documentation(e.g., shrink wrapped software or a magnetic tape), preloaded with acomputer system (e.g., on system ROM or fixed disk), or distributed froma server or electronic bulletin board over the communication system(e.g., the Internet or World Wide Web.)

Hardware logic (including programmable logic for use with a programmablelogic device) implementing all or part of the functionality previouslydescribed herein may be designed using traditional manual methods, ormay be designed, captured, simulated, or documented electronically usingvarious tools, such as Computer Aided Design (CAD), a hardwaredescription language (e.g., VHDL or AHDL), or a PLD programming language(e.g., PALASM, ABEL, or CUPL.)

While the invention has been particularly shown and described withreference to specific embodiments, it will be understood by thoseskilled in the art that various changes in form and detail may be madetherein without departing from the spirit and scope of the invention asdefined by the appended claims. As will be apparent to those skilled inthe art, techniques described above for panoramas may be applied toimages that have been captured as non-panoramic images, and vice versa.

What is claimed is:
 1. A system for creating a transition between afirst scene and a second scene simulating motion, the first sceneobserved from a first viewpoint including a first digital image and thesecond scene observed from a second viewpoint including a second digitalimage, the system comprising: a processor, the processor configured to:determine, for each digital image, a directional vector corresponding toa pan and tilt of a camera that captured the digital image; transform,for each digital image, corresponding digital image data to rotate thedigital image so that the directional vector of the transformed digitalimage is parallel to one of the axes of a global coordinate system;further transform digital image data of at least one of the transformeddigital images so as to align the directional vectors of the transformeddigital images, thereby achieving alignment of corresponding features ineach of the transformed digital images; define a common ground planeshared by the first transformed digital image and the second transformeddigital image; define a footprint of structures within the firsttransformed digital image and the second transformed digital image onthe ground plane; extrude geometries from the footprint, wherein thefootprint and the extruded geometries define a three-dimensionalgeometry representative of the structures; determine a view positionalong a path for a transitional image in relation to the threedimensional geometry; and projectively map data from the first digitalimage and the second digital image based on the three-dimensionalgeometry and the view position to create a transitional image.
 2. Thesystem according to claim 1, wherein the first digital image and thesecond digital image are representative of photographs.
 3. The systemaccording to claim 1, wherein the first digital image and the seconddigital image are panoramic images.
 4. The system according to claim 3,wherein the first and second digital images represent a 360 degree view.5. The system according to claim 1, the processor further configured to:display on a display the first digital image, one or more transitionalimages, and the second digital image sequentially.
 6. The systemaccording to claim 1, wherein the geometries include at least one of aperspective rectangle and a perspective triangle.
 7. The systemaccording to claim 1 wherein a plurality of transitional images arecreated from different positions along the path.
 8. The system accordingto claim 1, the processor further configured to: display on a displaythe first digital image with a first navigational icon embedded; andwhen the first navigational icon is activated, display the transitionalimage, such that there is simulated motion from the first digital imageto the second digital image.
 9. The system according to claim 8, whereindisplaying a transitional image includes at least one of alpha-blending,morphing and motion-blurring the first digital image and the seconddigital image.
 10. The system according to claim 1, the processorfurther configured to: display the first scene; receive an indication ofthe view position; and when the indication of the view position isreceived, display the transitional image that includes at least onetransitional scene, such that there is simulated motion from the firstscene to the second scene.
 11. A system for creating a transitionbetween a first scene and a second scene simulating motion, the firstscene observed from a first viewpoint including a first digital imageand the second scene observed from a second viewpoint including a seconddigital image, the system comprising: means for determining, for eachdigital image, a directional vector corresponding to a pan and tilt of acamera that captured the digital; means for transforming, for eachdigital image, corresponding digital image data to rotate the digitalimage so that the directional vector of the transformed digital image isparallel to one of the axes of a global coordinate system; means forfurther transforming digital image data of at least one of thetransformed digital images so as to align the directional vectors of thetransformed digital images, thereby achieving alignment of correspondingfeatures in each of the transformed digital images; means for defining acommon ground plane shared by the first transformed digital image andthe second transformed digital image; means for defining a footprint ofstructures within the first transformed digital image and the secondtransformed digital image on the ground plane; means for extrudinggeometries from the footprint, wherein the footprint and the extrudedgeometries define a three-dimensional geometry representative of thestructures; means for determining a view position along a path for atransitional image in relation to the three-dimensional geometry; andmeans for projectively mapping data from the first digital image and thesecond digital image based on the three-dimensional geometry and theview position to create a transitional image.
 12. The system accordingto claim 11, wherein the first digital image and the second digitalimage are representative of photographs.
 13. The system according toclaim 11, wherein the first digital image and the second digital imageare panoramic images.
 14. The system according to claim 13, wherein thefirst and second digital images represent a 360 degree view.
 15. Thesystem according to claim 11, the system further comprising: means fordisplaying on a display the first digital image, one or moretransitional images, and the second digital image sequentially.
 16. Thesystem according to claim 11, wherein the geometries include at leastone of a perspective rectangle and perspective triangle.
 17. The systemaccording to claim 11, wherein a plurality of transitional images arecreated from different positions along the path.
 18. The systemaccording to claim 11, the system further comprising: means fordisplaying on a display the first digital image with a firstnavigational icon embedded; and means for displaying the transitionalimage, such that there is simulated motion from the first digital imageto the second digital image when the first navigational icon isactivated.
 19. The system according to claim 18, wherein displaying atransitional image includes at least one of alpha-blending, morphing andmotion-blurring the first digital image and the second digital image.20. The system according to claim 11, the system further comprising:means for displaying the image of the first scene; means for receivingan indication of the view position; and means for displaying thetransitional image that includes at least one transitional scene, suchthat there is simulated motion from the first scene to the second scenewhen the indication of the view position is received.